Cranberry Lemon Sandwiches

1 cup butter, softened
1 cup shortening
1 cup sugar
1 cup confectioners' sugar
2 large eggs
2 teaspoons vanilla extract
4 cups all-purpose flour
1 teaspoon cream of tartar
1 teaspoon grated lemon peel
1/2 teaspoon salt
3/4 cup dried cranberries

2/3 cup butter, softened
2-3/4 cups confectioners' sugar
1/4 cup 2% milk
1-1/4 teaspoons grated lemon peel

In a large bowl, cream the butter, shortening and sugars until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in vanilla. Combine the flour, cream of tartar, lemon peel and salt; gradually add to the creamed mixture and mix well. Stir in cranberries. Cover and refrigerate for 2 hours or until easy to handle.

Roll into 1-in. balls. Place 2 in. apart on ungreased baking sheets. Flatten with a glass dipped in sugar. Bake at 350° for 12-14 minutes or until edges are lightly browned. Remove to wire racks to cool.

In a small bowl, combine the filling ingredients; beat until smooth. Spread on the bottoms of half of the cookies; top with remaining cookies. Makes about 4-1/2 dozen.